Delay Aversion in Attention Deficit/Hyperactivity Disorder: an empirical investigation of the broader phenotype.
BACKGROUND
Delay-related motivational processes are impaired in children with Attention Deficit/Hyperactivity Disorder (ADHD). Here we explore the impact of ADHD on the performance of three putative indices of Delay Aversion (DAv): (i) the choice for immediate over delayed reward; (ii) slower reaction times following delay; and (iii) increased delay-related frustration-to see whether these tap into a common DAv construct that differentiates ADHD cases from controls and shows evidence of familiality.


METHODS
Seventy seven male and female individuals (age range 6-17) with a research diagnosis combined type ADHD, 65 of their siblings unaffected by ADHD and 50 non-ADHD controls completed three delay tasks.


RESULTS
As predicted the size of the correlation between tasks was small but a common latent component was apparent. Children with ADHD differed from controls on all tasks (d=.4-.7) and on an overall DAv index (d=.9): The battery as a whole demonstrated moderate sensitivity and specificity. In general, deficits were equally marked in childhood and adolescence and were independent of comorbid ODD. IQ moderated the effect on the MIDA. Scores on the DAv factor co-segregated within ADHD families.


CONCLUSIONS
There is value in exploring the broader DAv phenotype in ADHD. The results illustrate the power of multivariate approaches to endophenotypes. By highlighting the significant, but limited, role of DAv in ADHD these results are consistent with recent accounts that emphasize neuropsychological heterogeneity.
Bitsakou
Paraskevi
P
Developmental Brain-Behaviour Laboratory, University of Southampton, UK.
Psychogiou
Lamprini
L
Thompson
Margaret
M
Sonuga-Barke
Edmund J S
EJ
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000523:psychology*; D007361:Intelligence Tests; D008297:Male; D009483:Neuropsychological Tests; D010641:Phenotype; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time; D012201:Reward; D011795:Surveys and Questionnaires; D013997:Time Factors